Engine starting apparatus



Aug. 7, 1956 L. C. DERMOND ENGINE STARTING APPARATUS Filed Sept. 25, 1953 my 714'? M5 [NVE-Mraz LA wies Ncf 6'. DEEMOND A T TOE/VE Y' United States Patent Office 2,758,163 Patented Aug. '7, 1955 ENGINE STARTING APPARATUS Lawrence C. Del-mond, Rochester,

General Motors Corporation, poration of Delaware N. Y., assigner to Detroit, Mich., a cor- This invention relates to starting apparatus for internal combustion engines and more particularly to those for automotive vehicles and especially to the semi-automatic type of starting apparatus in which a control switch for the starting motor circuit is automatically closed by operation of some one of the control instrumentalities of the vehicle, such as the carburetor throttle, for example, and is automatically prevented from closing during operation of the engine under its own power.

In starting apparatus of this character which employs engine suction to prevent closing of the switch during engine operation, it is difficult to design a control switch which will always be effective, under all operating conditions which may be encountered, to prevent closing of the switch during running of the engine and which will also, under no circumstances, elect opening of the switch during the cranking operation. This is due to the fact that under some extreme conditions of engine operation the engine suction, when the engine is operating under its own power, is approximately the same as the suction during cranking if the engine is relatively hot and the cranking speed high.

lt is the object of the present invention to provide a control switch for controlling the action of the starting motor in a control apparatus of the character referred to, which is operated by one of the vehicle control members, such as the throttle, and is prevented from being closed during operation of the engine under its own power, by engine suction; which is simple in construction, can be manufactured at low cost and which, while always effective to prevent closing of the starting motor circuit during engine operation, is never effective to open such circuit during the cranking period.

According to this invention, this object is attained by the provision of a contact moved with the throttle shaft after the throttle valve is partially open which is engaged by a second contact controlled by a latch member which, when the engine is inoperative, is moved to ineffective position so that the switch can close by a suction operated ball that is held in position where it has no effect on the latch member during operation of the engine under its own power. The latch member, when in operative position, is effective to positively prevent closing of the contacts of the control switch and occupies such position at all times when the engine is operating under its own power.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. l is a side elevation of the throttle body casting of the carburetor showing the switch housing which is formed thereon with the cover removed and parts of the switch in elevation.

Fig. 2 is a View similar to Fig. 1 with the cover on the switch housing.

Fig. 3 is a bottom plan View partly in section on line 3-3 of Fig. 5.

Fig. 4 is a section on the line 4 4 of Fig. l.

Fig. 5 is a section on line 5-5 of Fig. 3.

Fig. 6 is a detail view of the switch locking lever.

Fig. 7 is a view similar to Fig. l with the ball in its lower position.

The outlet or throttle body casting 1 of the carburetor has a bottom flange 2, which is secured to the manifold when the carburetor is assembled and is provided with openings 3 through which bolts pass to secure the carburetor in position. The construction of the carburetor is wholly immaterial so far as the present invention is concerned but it may be said for explanatory purposes that the carburetor is of the conventional downdraft type and the main body thereof is positioned above the outlet casting 1, so that air entering at the top is mixed with fuel to form a combustible mixture which lows downwardly and through the casting 1 into the manifold through the passages or outlets 4 and 5 which may be termed primary and secondary mixture passages respectively. These passages are controlled by primary and secondary throttle valves 6 and 7 secured in any desirable way to shafts 8 and 9, respectively, which are suitably journaled for rotation in the casting 1. These throttle valves are manually operated by mechanism which forms no part of this invention and is, therefore, not shown herein. However, the throttle operating mechanism is fully shown and described in the copending application of Olson et al. S. N. 264,136 filed December 29, 1951, and such mechanism is so designed that the throttles are not opened simultaneously, but concurrently, the secondary throttle 7 not being opened until the primary throttle is opened to some predetermined extent. This predetermined opening of the primary throttle is variable for different installations, but is generally about 40 degrees.

The switch which is the subject of this invention is operated by the primary throttle and to this end the shaft S extends beyond the wall of the main casting into the space 10 that lies within the wall 11, which is integral with and extends from the main casting 1, to form a housing for the switch parts. A cover 13, of Bakelite or other suitable insulating material, is secured to the housing by screws 14 and this cover carries the switch contacts 15 and 16 which are best shown in Fig. l. Contact 15 is riveted to a supporting bar 17 which is supported by the cover plate 13 and extends through the plate to the outside of the housing, as shown in Fig. 3. Outside the housing the bar 17 is engaged by the binding post 18 which extends through the bar and is screwed into the cover 13 and one wire of the control circuit which determines operation of the starting motor is adapted to be secured thereto. The other switch contact 16 is riveted to a similar supporting bar 19 which is carried by the cover plate and outside the plate is en gaged by binding post 20 which is arranged similarly to the post 18, and the other wire of the starter control circuit is adapted to be secured to the post Ztl. The two bars 17 and 19 are molded in position in the cover plate when the plate is formed and have holes at 21 through which the insulating material of the cover plate extends.

Positioned adjacent a ange 22 formed on the shaft 8 is a collar 23 and supported on the shaft, between the collar and end of the shaft, is an annular block of insulating material 24 which has a loose enough t on the shaft to permit the latter to rotate without rotating the insulating material. A part of the circumferential surface of this block of insulating material is of greater diameter than the remainder of such surface to form a cam 25 and this part of the block is formed with a chamber or pocket 26 therein, as best shown in Fig. 4. Surrounding and fitting tightly on the circumferential surface of the bloeit of insulating material 24, except that part of such surface as constitutes the cam Z is a metal band 27 which forms the movable contact of the switch and which may be any suitable metal, such as steel, brass or copper, for example. When the block 24 is rotated to a position where both contacts l5 and lo are in engagement with the band 27 the control circuit for the starter system is closed and the starting motor is energized, and when the band 27 is not engaged by both contacts l5 and lo the control circuit is open. The contact l5 engages the contact Z7 at all times but the Contact 16 is only permitted to engage the contact Z7 when the engine is inoperative and the throttle is moved toward its open position. Under all other conditions the Contact 16 is positively prevented from engaging contact 27.

At its extreme left end, as seen in Fig. 4, the shaft 3 is of reduced diameter forming a shoulder Z8, and positioned between the shoulder and the end of the shaft is a collar 2@ which has a bent over tang 30 which extends into the chamber 26 and the collar 29 is held in any desired position with respect to the throttle shaft by a screw 33t which passes through the collar, is screwed into the end of the shafts S and clamps the collar Z9 between itself and the shoulder 28. The collar 29 may be formed with a relatively narrow neck 32 between the main part of the collar and the tang 30 as shown in Fig. l or the neck may be of the same width as the tang if desired.

With the engine not running and the throttle in closed or idle position the tang 3@ is moved clockwise to such an extent that it engages the wall of the recess Z6 and moves the block of insulating material 24 to a position where the cam 25 engages the end of the contact lo moving such contact downwardly to the position shown in Fig. l and preventing any possible engagement of the contact lo with the metal band 27, so that the control switch is held open when the engine is inoperative and the throttle is closed, whereby the starting motor cannot be rendered effective until the throttle is moved toward open position. When the throttle is so moved the tang 3i) is moved counterclockwise, as seen in Fig. l, and after a certain degree of opening movement of the throttle, which is determined by the width of the tang 30, the magnitude of the recess 26 and the length of cam 25, the tang engages the right wall of the recess, as seen in Fig. l, moving the block 2d and cam 25 counterclockwise until the cam moves out of engagement with contact llo, permitting said contact to move into engagement with band 27 so as to close the control switch and cause the starting motor to be energized.

It will be understood that Contact lo is of resilient construction which is biased toward the contact band 27, so that when released from engagement with the cam 2S it will engage the band 27 with sucient force to etlect a good contact therewith and to move into engagement with the band with a snap action. To this end the Contact llo is bent to form a longitudinal rib 35 which resists downward movement of the contact by the cam 25 with considerable force and the end of the contact which engages the cam is bent over as indicated at 36, so that it presents a smooth rounded surface for engagement with the cam. The extent of opening of the throttle valve 6 which is necessary to close the control switch may be varied as desired, but it is always desirable to close the switch before the secondary throttle valve '7 is opened.

Closing of the control switch upon opening movements of the throttle during engine operation, such as are necessary to control the speed of operation of the vehicle, is prevented by a latch mechanism which is automatically operated by the engine suction which is maintained in the manifold and carburetor intake at points posterior to the throttle valves. This latch mechanism includes a lever designated generally by the numeral 37 which is shown in detail in Fig. 6. This lever comprises two arms 38 and 39 connected by a bridge member 40 and provided with openings 41 through which a pivot pin 4t2 extends, such pin being xedly mounted in a recess 43 in the wall of the carburetor casting in any suitable manner. The lever is held against movement longitudinally of the pivot pin by a cotter pin dei or in any other suitable way.

The lever arm 33 has a toe d5 which projects to the right below the throttle shaft S and that serves as a counterweight which is effective to rock the lever 3/ on its pivot in a clockwise direction when such movement of the lever is not prevented by other means. When the lever 37 is moved as described, by the ettect of the counterweight, a latch toe do is moved to the position shown in Fig. l where it is positioned immediately above a block 47 of some suitable insulating material that is riveted to the contact i6 and prevents any movement of such contact toward the Contact band Z7, when the toe 46 is in such position.

in order to control the position of the latch lever such lever has another toe liwhich projects to the left as seen in Fig. l to a position immediately below a bali 49 slidable in a vertical bore 5t* formed in the casting l. The bore is of such size at the lower end thereof that the ball tits loosely enough to be freely slidable therein but tight enough to insure that the bali will be lifted by the relatively high suction which is maintained posterior to the throttle when the engine starts to run under its own power and which is communicated to the bore Ea'tl above the ball. For this purpose the upper end of the bore 5@ connects with a horizontal passage 5l formed in the casting i and which is closed at one end by a plug 52 and at the other connects with a space or recess 53 in the housing. rthis recess is in communication with the intake manifold so that the high suction thereof is communicated directly to the cylinder or bore Sil above the ball.

The bore Si) is of three diameters, the lower or largest part of the bore being designated 5(9(1 and being of a size such as previously described. Immediately above the part Sila the bore is of somewhat reduced diameter and this part of the bore is designated Fitted tightly in this part 56h of the bore 513 is an angular washer 54 of annular form which is formed of some metal softer than iron or steel, such as copper, for example. This washer has an opening therethrough which is smaller than the ball and the ball seats against the washer as it is lifted upwardly by suction, when the engine begins to oper-ate under its own power. The ball will seat very accurately against the washer 54 completely closing the suction passage and making it possible for a very small amount of suction to hold the ball in its upper position.

Above the Washer 5d the bore 5t? is further reduced in size as indicated at Stic and this part of the bore connects with the suction passage 5l.

At the bottom of the housing l at a point where the housing extends beyond the main carburetor housing is a recess 55, in which is fitted a tine mesh screen 56, and connecting with the recess is an opening 57 which admits screened air to the inside of housing i to maintain atmospheric pressure, below the ball 49.

At a point adjacent the end of the throttle valve shaft the cover plate 13 has an opening ou in which a removable metal cap 6l has a snap fit. As shown in Fig. 3 the cap has a circumferential groove which snaps on a rib 615 formed on the cover plate 13 to hold the cap in place and the cap can be removed to permit access to the contact elements at the end of the throttle shaft without removing the entire cover plate.

The previously described switch operates in the following manner. Normally, the parts are in the position shown in Fig. 7, when the engine is not operating and the throttle is in closed or idle position. When the throttle is in such position the cam 25 engages the end 3d of switch contact ll6, holding such contact out of engagement with the movable contact Z7 and the ball rests 0n the toe 43 of the latch lever 37. The weight of the Weense ball is sufcient to move the toe 48 downwardly, disengaging the latch 46 from the block 47 on contact 16. Therefore, when the engine is not in operation the latch 46 does not control the movement of contact 16 and the latter is prevented from engaging the contact band 27 solely because of the fact that when the throttle is in closed position the cam 25 is moved to such a position that it engages and depresses the end of contact 16.

In order to effect closing of the switch when the parts are in the Fig. 7 position the throttle is moved towards open position. This will move the tang 3i) counterclockwise, as seen in Fig. l, and after a predetermined movement such tang will engage the wall of recess 26 so that block 24 will then be moved with the throttle shaft, After a further predetermined movement of the throttle toward open position, dependent upon the shape of cam 25, such cam is moved out of engagement with the end 36 of contact 16 and such end snaps into engagement with the contact 27 to eiect closing of the switch. This will cause the conventional starting motor to rotate or crank the engine for starting puposes. As long as the engine is being rotated by such starting motor the suction effective on the ball 49 is insuflicient to lift the ball and the latch lever will remain in the Fig. 7 position until the engine starts to run under its own power. When this occurs, the suction is greatly increased, the ball is lifted against seat 54 and the latch lever will rotate clockwise until the latch 46 engages the right side of block 47. It cannot move into the latching position of Fig. l until the contact 15 is depressed enough for the latch to clear the edge of block 47, and this occurs when the switch is opened after the engine has started.

The lifting of ball 49 does not open the switch, it merely prevents reclosing of the switch after it is once opened, until the engine becomes inoperative. The opening of the switch is effected manually by releasing the throttle to allow the conventional throttle return spring to return the throttle to closed or idle position. This moves cam 25 back to its original position where it engages end 36 of contact 16 moving such contact to the position shown in Fig. l. When this takes place, the ball 49 being held in its upper position by suction, the latch lever 37 rotates in a clockwise direction because of the excess weight to the right of the pivot pin 42 and takes the position shown in Fig. l, with latch 46 immediately above the block 47. With the parts in this position, if the throttle is opened to increase the speed of the engine, the cam 2S will be moved out of engagement with the contact 16, and the latter, being biased upwardly would tend to move into engagement with the contact 27 but is prevented from doing so by engagement of block 47 with latch 46. In this way any closing of the control switch during operation of the engine is prevented,

The suction effective on the ball should be sufficient to hold the ball in its upper position under all operating conditions when the engine runs under its own power, but if under some very extreme condition, with the throttle wide open, the suction on the ball would become insuicient to hold it up, the switch would not be closed. The contact 16 is biased toward contact 27 with such force that the friction between latch 46 and block 47 is too much to be overcome by the weight of the ball and the latter would not disengage the latch from the block. If the throttle was moved to closed position this friction would be eliminated but, under such conditions the suction on the ball is always very high and the ball would be held in its upper position.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

l. In an electric starting apparatus for an internal combustion engine having a carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually movable throttle shaft for regulating the quantity of such mixture delivered to the engine, a control switch for controlling the operation of such apparatus having in combination; a contact movable into position to effect closing of the switch, means normally preventing movement of said contact to switch closing position, a member operatively connected to the throttle and movable thereby to engage and move said last named means to a position where such means is inoperative, a latch for also preventing movement of said contact to switch closing position, operating means for said latch movable relatively thereto and movable to a position where the engine is running to render said latch effective so as to prevent closing of the switch during self operation of the engine, said means being movable to a position when the engine stops to render said latch ineffective.

2. In an electric starting apparatus for an internal combustion engine having a carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually movable throttle shaft for regulating the quantity of such mixture delivered to the engine, a control switch for controlling the operation of such apparatus having in combination; a contact movable into position to effect closing of the switch, means normally preventing movement of said contact to switch closing position, a member operatively connected to the throttle and movable thereby to engage and move said last named means to a position to render said last named means inoperative upon a predetennined opening movement of the throttle, a latch for also preventing movement of said contact to switch closing position, operating means for said latch movable relatively thereto and movable to a position where the engine is running to render said latch effective so as to prevent closing of the switch during self operation of the engine, said means being movable to a position when the engine stops to render said latch ineffective.

3. In an electric starting apparatus for an internal combustion engine having a carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually movable throttle shaft for regulating the quantity of such mixture delivered to the engine, a control switch for controlling the operation of such apparatus having in combination; a contact movable into position to effect closing of the switch, means normally preventing movement of said contact to switch closing position, a member operatively connected to the throttle and movable thereby to engage and move said last named means to a position where such means is inoperative, a latch for also preventing movement of said contact to switch closing position, operating means for said latch movable relatively thereto and movable by engine suction when the engine is running to a position to render said latch effective so as to prevent closing of the switch during self operation of the engine and movable to a position when the engine stops to render said latch ineffective.

4. In an electric starting apparatus for an internal combustion engine having a -carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually operable throttle shaft for regulating the quantity of such mixture delivered to the engine; a control switch for controlling the operation of such apparatus having in combination a contact carried by said throttle shaft, a second contact movable into engagement with the first contact to effect closing of said switch, a latch for controlling movement of said second contact to switch closing position, operating means for said latch movable relatively thereto and movable by engine suction, when the engine is self-operative to a position to cause the latch to be moved to its effective position so as to prevent closing of the switch during engine operation, said operating means for the latch beannales 7 ing movable when the engine stops to engage and move the latch to ineffective position.

5. In an electric starting apparatus for an internal combustion engine having a carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually operable throttle shaft for regulating the quantity of such mixture delivered to the engine; a control switch for controlling the operation of such apparatus having in combination a contact movable into a position to effect closing of the switch, a second contact movable into engagement with, the first Contact to effect closing of the switch after the first contact has been moved to a predetermined position, a latch for controlling movement of said second Contact to switch closing position, a member movable to a position to engage and move the latch to ineffective position when the engine is inoperative, means wh said member is moved out of engagement with f when the engine is self-operative, and means for ing the latch to effective position when said membc` disengaged therefrom so as to prevent closing of the switch when the engine is running.

6. in an electric starting apparatus for an internal combustion engine having a carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually operable throttle shaft for regulating the quantity of such mixture delivered to the engine; a control switch for controlling the operation of such apparatus having in combination a contact movable into a position to effect closing of the switch, a second Contact movable into engagement with the first contact to effect closing of the switch after the first contact has been moved to a predetermined position, a latch for controlling movement of said second contact to switch closing position, operating means for said latch movable relatively thereto and movable by engine suction when the engine is self-operative to a position to cause the latch to be moved to its effective position so as to prevent closing of the switch during engine operation, said operating means for the latch being movable by gravity when the engine stops to engage and move the latch to ineffective position.

7. in an electric starting apparatus for an internal cornbustion engine having a carburetor for supplying conibustible mixture thereto provided with a throttle valve operable by a manually operable throttle shaft for regulating the quantity of such mixture delivered to tne engine; a control switch for controlling the operation of such apparatus having in combination a member supported on the throttle shaft and movable relatively thereto, a movable Contact carried by said member, an actuating element secured to the throttle shaft so as to be movable therewith and adapted to engage and move said member with the throttle after a predetermined movement of the latter toward throttle open position, a second contact adapted to engage said movable contact after the latter has been moved to a predetermined position by movement of the throttle, a latch member for controlling movement of the second contact into engagement with. the first contact, means operable when the engine is inoperative to release the latch member and permit engagement of the switch contacts and operable when the engine is operating under its own power to cause the latch to prevent engagement of said contacts, so that operation of the starting motor is prevented when the engine is self operative.

8. in an electric starting apparatus for an internal combustion engine having a carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually operable throttle shaft for regulating the quantity of such mixture delivered to the engine; a control switch for controlling the operation of such apparatus having in combination a member supported on the throttle shaft and movable relatively thereto, a movable contact carried by said member, an actuating element secured to the throttle shaft so as to be movable therewith and adapted to engage and move said member with the throttle after a predetermined movement of the latter toward throttle open position, a second contact adapted to engage said movable contact after the latter has been moved to a predetermined position by movement of the throttle, a latch member for controlling movement of the second contact into engagement with the first contact, means operable when the engine is inoperative to release the latch member and permit engagement of the switch contacts and movable by engine suction when the engine is self operative to a position to cause the latch to prevent engagement of said switch. contacts in order to prevent operation of the starting motor.

9. ln an electric starting apparatus for an internal combustion engine having a carburetor for supplying com.- bustible mixture thereto provided with a throttle valve operable by a manually operable throttle shaft for regulating the quantity of such mixture delivered to the engine; a control switch for controlling the operation of such apparatus having in combination a member supported on the throttle shaft and movable relatively thereto, a movable Contact carried by said member, an actuating element secured to the throttle shaft so as to be movable therewith and adapted to engage and move said member with the throttle after a predetermined movement of the latter toward throttle open position, a second contact adapted to engage said movable contact after the latter has been moved to a predetermined position by movement of the throttle, a latch member for controlling movement of the second contact into engagement with the first Contact, means movable when the engine is inoperative to a position to engage and move the latch member to ineffective position, so as to permit engagement of said switch contacts and movable to a position out of engagement with the latch member when the engine is self operative to permit movement of the latch member to its latching position, so that closing of the contacts and operation of the starting motor is prevented when the engine is running.

l0. In an electric starting apparatus for an internal combustion engine having a carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually operable throttle shaft for regulating the quantity of such mixture delivered to the engine; a control switch for controlling the operation of such apparatus having in combination a member supported on the throttle shaft and movable relatively thereto, a movable contact carried by said member, an actuating element secured to the throttle shaft so as to be movable therewith and adapted to engage and move said member with the throttle after a predetermined movement of the latter toward throttle open position, a second contact adapted to engage said movable contact after the latter has been moved to a predetermined position by movement of the throttle, a latch member for controlling movement of the second Contact into engagement with the first contact, a member movable by gravity when the engine is inoperative to engage and move the latch member to ineffective position to permit closing of the switch contacts and operation of the starting motor, said member being movable by engine suction, when the engine is self operative, to a position out of engagement with the latch member to permit movement of the latch member to effective position.

1l. in an electric starting apparatus for an internal combustion engine having a carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually operable throttle shaft for regulating the quantity of such mixture delivered to the engine; a control switch for controlling the operation of such apparatus having in combination a member supported on the throttle shaft and movable relatively thereto, a movable contact carried b y said member, an actuating element secured to the throttle shaft so as to be movable therewith and adapted to engage and move said member with the throttle after a predetermined movement of the latter toward throttle open position, a second contact adapted to engage said movable contact after the latter has been moved to a predetermined position by movement of the throttle, a pivoted latch member for controlling engagement of the switch contacts, a member movable, when the engine is inoperative, to a position to engage and move the latch member to ineffective position and movable to a position out of engagement with the latch member when the engine is self operative, and means operable to move the latch member to its effective position when said last named member is moved out of engagement therewith, so that closing of the control switch is prevented when the engine is running.

12. In an electric starting apparatus for an internal combustion engine having a carburetor for supplying combustible mixture thereto provided with a throttle valve operable by a manually operable throttle shaft for regulating the quantity of such mixture delivered to the engine; acontrol switch for controlling the operation of such apparatus having in combination a member having a recess therein supported on the throttle shaft and movable relatively thereto, an actuating nger secured to the throttle and extending into said recess and eiective to engage the end of said recess and move said member with the throttle shaft after a predetermined movement of the latter from closed position, a movable contact carried by said member, a second contact engageable with said first contact after the rst Contact moves to a predetermined position and means operative to prevent engagement of said contacts when the engine is self operative.

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